Brake shoe grinder



Nov. 26, 1940. H. THOMASON BRAKE SHOE GRINDER Filed Sept.

L957 3 Sheets-Sheet l INVEIJJOR. ff b/mar 7720220500 A TTORNEY.

Nov. 26, 1949. THQMASQN 2,222,640

BRAKE SHOE GRINDER 1 Filed Sept. 22, 1937 3 Sheets-Sheet 2 imp \[Tnr INVENTOR. Aye/mar mormzyofl ATTORNEY.

Nov. 26; 1940. v THOMASQN 2,222,640

BRAKE SHOE GRINDER Filed Sept. 22, 193"! 5 Sheets-Sheet 3 48 INVENTOR. g fj'a/mar Thu/nasal? 5 BY 50 i ATTORNEY.

Patented Nov. 26, 1940 UNITED STATES This invention relates to'improvements in a brake shoe grinder and gauge and may be considered as an improvement over the disclosure set forth in my copending application Serial No. 746,665, filed October 3, 1934, which has becom Patent No. 2,145,902.

An object of the invention is to provide an regardless of its taperor length and also it isto be mounted on any conventional form of axle.

Another object of the invention is to provide a relatively simple, durable, and effective chucking means which can be easily applied and which forms an accurately concentric surface on which the frame supporting the grinder may be mounted for rotation.

A further object of the invention is to provide a brake shoe grinder wherein the grinder may be optionally mounted so that its axis of rotation is either substantiall parallel to the axis of the spindle or axle or so that its axis of rotationis approximately radial thereof. In the latter position a small or thin grinding wheel may be employed for grinding the brake shoes beneath inturned edges of the dust shield which is frequently employed in brake constructions to prevent entry of water, dust, or dirt.

Another object of the invention is to provide a brake shoe grinder and gauge wherein provision is made for the accurate application of a micrometer in such a position that the center or diameter measured by the micrometer will be coincident with the axis of theaxle or spindle.

A still further object of the invention is to provide a brake shoe grinder and gauge wherein there is a chucking. means applicable to the spindle or axle 0n which is rotatably mounted the grinder and to provide adjustable stops limiting the inward movement of the grinder to a predetermined radius and to provide means for feeding the grinder against the work until stopped by the adjustable stops.

With the foregoing and other objects in view, which will be made manifest in the following detailed description and specifically pointed out in PATENT OFFICE 2,222,640 BRAKE SHOE GRINDER Hjalmar Thomason, Los Angeles, Calif. Application September 22, ,1 9? 7, Serial No. 165,124 g 8 Claims. (01. 51-241 the appended claims, reference is had to the accompanying drawings for an illustrative embodiment of the invention, wherein:

Figure l is a view in end elevation of the improved brake shoe grinder and gauge;

Fig. 2 is a view in side elevation of the same, illustrating in dotted lines the position assumed by the micrometer and illustrating the brake shoe grinder and gauge as applied to a taperedspin dle;

Fig. 3 is a'view in side elevation, parts being broken away and shown in vertical section, illustrating the details of the chucking means;

Fig. 4 is a sectional view taken substantially upon the line 4-4 upon Fig. 3; and

Fig. 5 is a View in side elevation of the grinder illustrating the construction wherein the grinder is in a position wherein its axis of rotation is disposed substantially radial of the axle or spindle to which the device is applied.

Referring to the accompanying drawings wherein similar reference characters designate similar parts throughout, the improved grinder comprises a type of chucking means generally designated at III which consists of a slotted inner chucking sleeve I I having slots I2. The slots are preferabl three in number, although the number may be increased. One end of the sleeve is enlarged as at I3 and externally threaded as at [4 to receive a threaded ring or nut I5. In this enlarged portion of the sleeve in alinement with slots l2 there are formed three radial apertures I8 which receive radially slidable pins FL.

The inner ends of the pins I! are designed to engage around the inner end of the spindle or axle l8. Holes I9 are drilled into the end of the sleeve to provide spring pockets for springs 20 which urge bolts 2| into grooves or keyways 22 in the pins. The pins are thus frictionally held in any adjusted position within the enlargement I3 of sleeve II. An internally coned ring 23 engages the tapered or beveled ends 24 on the outer ends of the pins. This ring is advanced back and forth along the enlargement I3 of sleeve II bythe ring or nut I5. The connection between these two parts consists of a split-spring ring 25 which is compressed into a groove 26 until the ring or nut I5 is applied and then partial-- -1y expands into the groove in ring I5. This enan internally coned ring by a split-spring ring 3! in a manner similar to that previously described.

Ring 30 engages the beveled ends of pins 32 which are radially slidable through apertures 33. Holes 34 provide spring pockets and springs 35 and bolts 36 which frictionally hold the pins 32 in any adjusted position. In this manner, ring 21 may be longitudinally adjusted to any desired position along the length of sleeve ll 50 as to properly position its pins at the outer end of the axle or spindle l8. The outer end of the sleeve H is internally enlarged as indicated at 37. It is externally enlarged as indicated at 38 and the external surfaces on enlargements 38 and rings 23 and 30 are preferably hardened and ground on the same diameter so as to snugly receive an outer or second sleeve 40, The outer or second sleeve 40 has an internal annular groove 4l formed thereon adjacent one end which is adapted to be entered by a bolt 42 recessed within enlargement 38 but which is adapted to be moved into the groove by means of a rotary cam 43. When the cam 43 moves bolts 42 into groove 41, the outer sleeve 40 is locked against longitudinal movement relative to the chucking means but it may freely rotate thereon on the hardened and ground surfaces of enlargements 38 and rings 23 and 30.

The grinder is carried by a suitable frame consisting of two standards 44 and 45 which slidably extend through a clamp 46 which is clamped around the outer or second sleeve 40. The two standards have their lower ends clamped as indicated at 41 and 48 in a yoke 49 which carries a hand screw 50 threaded through the yoke and rotatably connected as at 5! to the bottom of the clamp 46. Stop collars 52 and 53 are adjustable along the standards and may be set in any adjusted position by means of set screws 54. These stop collars are engageable with the top of the clamp 46 to limit the inward radial movement of the grinder.

The grinder consists of a suitable motor 55 which carries a grinding wheel 56 preferably suitably housed within a dust collector 5'! which in turn is connected to a tube 58 which may lead to a vacuum or suction fan for conveying 01f the grindings. The motor of the grinder is suitably supported within a saddle 59 carried by the tops of the standards. In the sides of the saddle are formed T-shaped slots 60 which receive the studs 6| on the motor so that on tightening nuts 62 the grinder may be positioned inwardly or outwardly with respect to the saddle. The saddle may also carry a suitable gauge bar 63 which is adjustable relatively thereto. The clamp 46 is provided with an aperture 64 for the reception of an arm 65 on a micrometer 66. The aperture 64 is positioned a predetermined distance from the axis of the spindle l6 and the arm 65 on the micrometer is positioned the same distance from the center of the micrometer. The micrometer employed is such that, when adjusted, both ends are simultaneously expanded or retracted so that whenever the micrometer is in position with its arm 65 extending into the aperture 64, the center of the diameter measured by the micrometer is coincident with the axis of the spindle.

The operation and advantages of the improved brake shoe grinder and gauge are as follows: The micrometer may be applied to the brake drum to ascertain its diameter and then applied directly to the clamp 46, By adjusting hand screw 50, either the gauge bar 63 or the grinding wheel 56 may be properly and accurately positioned with respect thereto. By swinging the micrometer around arm 65 as a'center and adjusting either the grinder or the gauge bar to the top of the arc traversed by the top of the micrometer, it is possible to accurately position either the gauge bar or the grinder with respect to the axis of the axle or spindle l8.

In applying the construction to an axle or spindle l8 the inner sleeve H and associated structure is slipped over the spindle or axle. The nut or ring I5 is first tightened to advance ring 23 and force pin l1 into chucking engagement with the inner end of the spindle. Ring 21 is adjusted along the sleeve II to any desired position and ring 29 then rotated to advance ring 30 and to force pin 32 into chucking engagement with the outer end of the spindle. The outer sleeve 40 around which is clamped clamp 46 and the frame of the grinder is then slipped onto the chucking means and locked in position by rotating cam 43. In this condition the grinder, gauge bar, frame, clamp 46, and sleeve 40 may all rotate around the chucking means as a center and consequently, this entire structure is rotatable about the center or axis of the axle or spindle.

When the gauge bar is employed the brake shoes may be accurately set with respect thereto. In grinding brake shoes the grinder is caused to move through the proper circle concentrically with the axis of the axle or spindle and to accurately and properly grind the brake shoe.

In Fig. 5 I have illustrated how the construction may be modified in grinding brake shoes. To this end the motor is provided with an arm H which carries standards '12 and nut 13. The arm is designed to fit within the saddle 59 and the standards to assume adjusted positions within the T-slots 60. In this position the axis of rotation of the motor 10 is substantially radial with respect to the axis of the chucking means, and consequently the axis of the axle or spindle. With the motor thus applied a relatively thin grinding wheel 74 may be applied to the rotor for grinding the rear portions of the brake shoes which may be beneath inturned edges of dust shields on the brakes, It will be understood that the relatively thin peripheral edge of the grinding wheel may extend beneath this inturned edge in grinding entirely across the brake shoes.

From the above-described construction it will be appreciated that the improved brake shoe grinder and gauge is of relatively simple and very durable construction. It enables the application of the device to many different types of axles and spindles regardless of whether the axles are cylindrical or the spindles are tapered and regardless of the length and tapers of the spindles. The chucking means when thus conveniently applied forms a true surface concentric with respect to the axis of the axle or spindle on which sleeve 40 may be mounted to properly swing the grinder or gauge bar concentrically about the axis of the axle or spindle.

Various changes may be made in the details of construction without departing from the spirit or scope of the invention as defined by the appended claims.

I claim:

1. A chucking means for a brake shoe grinder having a slotted sleeve adapted to be positioned around an axle, a ring longitudinally slidable on the sleeve carrying pins radially adjustable through the slots, and means carried by the ring for tightening the pins against the axle or spindle.

2. A chucking means for a brake shoe grinder comprising a chucking structure constructed and adapted to be placed on an axle of an automobile and extending longitudinally thereof, said structure having a set of radial apertures with pins slidable therein and means to actuate said pins to contact the axle by the inner end of said pins, a ring movably mounted on said structure, the said ring having radial apertures with a second set of pins in said latter apertures and an adjusting means on the second ring to engage the inner end of the second pins with the axle, whereby the two sets of pins may engage the bearing surfaces of axles of various lengths and clamp the chucking means to the axle.

3. A chucking means for a brake shoe grinder comprising a slotted chucking sleeve adapted to be positioned around an axle, said sleeve having radial apertures, a first set of pins slidable therethrough, means for tightening the first pins into engagement with the axle, a ring freely slidable longitudinally on the sleeve and having a second set of pins slidable radially as to the ring and extending through the slots of the sleeve, means for tightening the second pins into engagement with an axle and the second sleeve and an outside sleeve rotatably mounted on the chucking sleeve and positioned outside of the outer ends of the pins.

4. A chucking means for a brake shoe grinder comprising a chucking sleeve having longitudinal slots adapted to be positioned around an axle, said sleeve having a solid portion with radial apertures, a first set of pins slidably mounted through the apertures, means interacting with the said sleeve for tightening said first pins into engagement with an axle, a ring longitudinally slidable as to the chucking sleeve andhaving inwardly extending portions engaging in the said slots, said ring having a second set of radial apertures with a second set of pins slidable in said latter apertures, means coacting with the ring to tighten said second pins into engagement with an axle, an outer sleeve positioned outside of the chucking sleeve, means forming a rotational bearing between the chucking sleeve and the outer sleeve, an interlocking means between the chucking and the outer sleeve to restrict the outer' sleeve from longitudinal movement but to permit its rotation relative to the chucking sleeve.

5. In a device as described, a chucking means constructed and adapted to engage an axle and having a peripheral cylindrical bearing surface combined with an outer sleeve rotatably mounted on such bearing surface, the chucking device having a radial slot with a locking bolt and a-cam intersecting such slot and reacting on the bolt to engage the bolt and the sleeve, said sleeve having an annular track for the bolt whereby the sleeve may rotate as to the chucking means but is prevented from longitudinal movement.

6. A chucking means for a brake shoe grinder adapted to be positioned around an axle of an automobile, said chucking means providing elements for carrying two independent sets of pins radially slidable through openings, means for independently tightening the pins of each set into engagement with the axle, means by which one set of pins may be moved longitudinally on the axle in relation to the other set of pins so as to engage the bearing surfaces of an axle of various lengths.

7. A chucking device including a sleeve-like structure adapted to encircle an axle and having a portion thereof externally threaded with a second nut threaded on the threaded ring and an interengaging means between the threaded ring and the second coned ring for longitudinal movement of the second coned ring whereby both sets of pins may be operative to engage a cylindrical or tapered axles.

8. A chucking device including a sleeve-like structure adapted to encircle an axle and having a portion thereof externally threaded with radial apertures adjacent the threads, a pin slidably mounted radially in each aperture, a wedge-like internally coned ring engaging the outer ends of the pins, a nut rotatable on the threads, complementary thrust surfaces on the nut and the coned ring operative in one direction of rotation and threading of the nut to longitudinally wedge the coned ring against the pins and an interlocking pulling means between the nut and the ring threading the nut in a reverse direction.

HJALMAR THOMASON. 

